Healthy Living: Elderberry juice

Somewhere I heard you can make a syrup (or something) of elderberry juice to use for nausea and upset tummy. It was last summer, and our elderberries here were done when I had read it, so didn't pay it much attention.

Looks like we're going to have a humongous crop of elderberries here in our neck of the woods if the blossoms on the bushes are any indication.

Does anyone know how to make this syrup and how to store it? Can it be put in the freezer, or would it have to be processed...i.e. pressure canned?

I guess you can buy something like this, but would like to try making my own. At least I would know it wouldn't have any added "crud" in it.